Future Me - Send an email to your future self
Handwrytten - Handwritten notes straight from your device. Huge selection of cards or design your own. Handwriting service integrates with 1000's of apps.
PastPost - Send a letter to your future self
Felt for iPhone - Handwritten cards for the modern world
Letter from You - Handwritten letter, mailed for you in the future.
Postpone Pixel - Send a photo to yourself or a friend in the future